Examples of mold handling systems are disclosed in the following U.S. Pat. No.: 3,827,549 to Hunter entitled “Extended Cooling Conveyor”; U.S. Pat. No. 4,589,467 to Hunter entitled “Mold Handling System”; U.S. Pat. No. 5,901,774 to Hunter et al. entitled “Linear Mold Handling System With Double-Deck Pouring And Cooling Lines; U.S. Pat. No. 5,927,374 to Hunter et al. entitled “Manufacturing Sand Mold Castings”; U.S. Pat. No. 5,971,059 to Hunter et al. entitled “Molding And Casting Machine”; and U.S. Pat. No. 6,145,577 to Hunter et al. entitled “Linear Mold Handling System”; and pending patent application Ser. No. 10/133,824 entitled “Method for Forming Sand Molds and Matchplate Molding Machine for Accomplishing Same”; all of which are assigned to the present assignee, and all of which are hereby incorporated by reference.
As disclosed in the foregoing patents, mold handling systems receive sand molds from one or more sand molding machines and then convey molds in an organized manner on a conveyer system to allow for pouring of molten material into sand molds and/or cooling of molten material poured into sand molds. The mold handling systems are typically interposed between a mold making machine and a shakeout conveyor where harvest of castings occurs. Mold handling systems may include rotary conveyors as disclosed in the '467 patent or linear conveyors as disclosed in the '549, '774, '374, '059 and '577 patents.
While these foregoing patents disclose significant technological innovations and improvements in the mold handling system art and have advanced automation in the mold making industry, there are still deficiencies existing with the apparatus and methods associated with making and handling sand molds to produce metal castings. One issue is that problems with the formation of sand molds or quality problems with castings being formed may not be discovered until a late stage. For example, each time a metallurgical mixture of molten metal is created in a ladle, it often takes a long time, typically more than an hour, for lab tests to determine if the metal poured from each ladle is of an acceptable metallurgical characteristic. There are other reasons such as mold flask, matchplate or squeeze head problems at the sand molding machine that may create improperly shaped internal cavities in the sand molds. As a result, defective castings or waste product may be produced and not discovered until a late stage. As a result, defective castings may be mixed with good quality product when the castings are output and then harvested on the shakeout conveyor.